Although I suspect there may be even cleaner ways to do it, you could
use a replacement rule such as
F[w]*Exp[I*w*t]/.{Exp[g:(restOfExponent__*w)]->Exp[restOfExponent*(x
+s*a)]}
This rule works for any sequence of multiplications in the exponent,
so long as w is somewhere and there actually IS a multiplication, i.e.
it doesn't work for w alone. To remedy that situtation, you could also
include a specific replacement for Exp[w],
Exp[w]->Exp[x*s+a]
This being said, I'd guess that there's a way that would get both
cases at once.
Jesse Woodroffe
On Apr 6, 3:44 am, "KFUPM" <hussain.alqaht... at gmail.com> wrote:
> Dear Group
>
> If i have a term like : F[w]*Exp[I*w*t] where F[w] is an arbitrary
> function, and i want to replace w by x+ s*a only in the exponent not
> in F[w], i wonder what is the quickest and easiest way to do it
> provided that i have so many similar terms.
>
> Your help and prompt reply is highly appreciated.
>
> HMQ